Method of constructing a vehicle axle housing



R. J. WILLIAMS Filed Dec. 29, 1951 July 3, 1956 IWETHGD F CONSTRUCTING A VEHICLE AXLE HOUSING Richard J. Williams, Birmingham, Mich., assignor to American Metal Products Company, Detroit, MICIL, a corporation of Michigan Application December 29, 1951, Serial No. 264,072 1 Claim. (Cl. 29-463) This invention relates to axle housings, and particularly to an axle housing and the method of construction.

in the past, it has been the practice on heavy trucks to make axle housings from seamless tubing which had one end hot-forged to form a spindle and the opposite end expanded to form one-half of a banjo housing provided at the center of the axle housing. Two of the parts so formed were then butt-welded at the banjo housing halves to form a circular banjo housing in the center of the assembly, with spindles at the opposite ends thereof. Spring pads were provided between the hub and the banjo housin which supported the sprung load of the body and which therefore applied the load directly to the cylindrical tube portion between the central banjo housing and the spindles. Because the maximum stress was applied at the tubular portion of the axle housing, the tubular members from which the housing was constructed required heavy walls to withstand the fatigue strains to which they were subjected.

In practicing the present invention, the portions of the axle housing which formerly were of cylindrical cross section between the banjo housing and the spindles are made square to provide flat side walls which are parallel to the applied load. The strength provided to the housing is substantially increased and thereby permits the thickness of the tubular wall to be substantially reduced, which permits a much thinner walled tube to be employed in the construction. Not only does this reduce the thickness of the cylindrical wall and the cost of the two lengths of tubing employed in the axle housing construction when made of seamless tubing, but also permits the use of cheaper resistance welded tubing which still further reduces the cost of the tube blanks which heretofore were of the seamless type because of the required heavy wall thickness.

Accordingly, the main objects of the invention are: to form an axle housing with the portions between the spindle ends and the central banjo of square section to substantially increase the strength thereof while reducing the thickness of tube wall and permitting the use of resistance welded tube blanks in the construction of the housing; to provide a method of constructing an axle housing from light tubular material of the seamless or resistance welded type which substantially increases the strength of the housing and reduces the cost of the tube blanks from which the housing is constructed; and, in general, to provide an axle housing which is simple in construction by a method which is economical.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawing, wherein:

Figure l is a view in elevation of an axle housing constructed by a method of the present invention;

Fig. 2 is an enlarged broken View of the left-hand end of the axle housing illustrated in Fig. 1;

2,752,673 Patented July 3, 1956 Fig. 3 is a broken view of the axle housing illustrated in Fig. 2, as viewed from the left-hand end thereof;

Fig. 4 is a sectional view of the structure illustrated in Fig. 2, taken on the line 44 thereof;

Fig. 5 is a sectional view of the structure illustrated in Fig. 2, taken on the line 5-5 thereof;

Fig. 6 is a broken, sectional view of the structure illustrated in Fig. 2, taken on the line 6-6 thereof, and

Fig. 7 is a broken view of the end of the tube before the end is expanded to the form illustrated in Fig. 2.

The axle housing of the present invention is constructed from a pair of tubular blanks of cylindrical section which are cold-reduced to the necessary diameter and length to provide the volume of metal required to forge the wheel supporting spindles. One end of the blank is forged into the cylindrical supporting spindle which is of smaller diameter than the original tube blank. The tube end which is forged into the spindle is then pushed through a square die which cold-works the tube wall at the portion 13 to reduce the tube and change its shape from circular to square section. The square reduction is stopped at a point which leaves a suificient length beyond the portion 13 of the original tube blank to form the banjo in a subsequent operation.

The remaining round end of the original tube diameter is heated and the side walls notched at 16, as illustrated in Fig. 7, to split the end into two sections which are wedged outwardly and formed in a die to the shape of a half banjo. The square section 13 blends into a rectangular section 14 which blends into an arcuate section 15 of channel shape at the ends, of sufiicient length to pro vi-de burn-off metal for butt-welding. Two of the blanks thus formed are butt-welded together at the half-banjo ends along the line 18 to form a circular banjo portion 19 at the center of the assembly from which the arm portion 20 extend in aligned relation, terminating in the spindles 11. The opposite faces and the inside diameter of the banjo portion are machined and the flash is cut from the weld lines 18 on the inside of the banjo portion.

The brake drum supporting flanges 21 and the spring pads 22 are tack-welded in position on the assembled housing, and a reinforcing ring 27 is welded to each outer face of the banjo portion along the inner line 28 and the outer line 29, as illustrated in Fig. 3. The welds are formed separately in a welding machine which revolves the housing about the center of the banjo portion.

It will be noted that the pad 22 is a forging having at the forward and rear ends projecting flanges 23 and 24 joined by a web portion 25 which encompasses the top portion of the square section of the housing. The forward flange 24 is disposed lower than the rear flange 23 so as to have the top surface 26 of the pad aligned with the ends of the flanges 23 and 24 and disposed at an angle to the top surface of the housing.

The flanges 21 and spring pads 22 are welded securely to the housing which inherit-treated thereafter, sand blasted and straightened. The internal and external surfaces of the spindles 11 may be machined or the machining may be undertaken later by the manufacturer of the vehicle. Thus, the housing has a spindle 11 at each end of reduced diameter and blends from circular to square at the portion 12 from which it extends at the portion 13 in square section and blends at the portions 14 and 15 into the banjo portion at the center of the housing.

Substantial advantage is provided by the method employed in the square arm construction of the axle housing, first, in the saving of metal in the tube blanks from which the housing is constructed, and second, in the possibility of using cheaper welded tubing because of the thinner wall construction. A further advantage is provided when using welded tubing because the wall thickness is uniform, being maintained between plus and minus 3 010 of an inch, while the seamless tubing walls vary in hickness from a plus or minus 10% of Wall thickness of size of tube ordered.

The varying wall thickness in the seamless type tubing as compared to the relatively close tolerance of the welded tubing adds to the difficulty of forging and fabricating of the blanks. This variation in wall thickness also requires the designer to over-design the housing to compensate for the possible minimum tolerances.

What is claimed is:

The method of forming an axle housing which includes the steps, of increasing the Wall thickness of a tubular blank by cold-working, of hot-forging one end of the blank to form a spindle thereon, of forcing the opposite end of the blank through a squarer ring die to provide a square section to the blank which blends into the cylindrical portion adjacent to said spindle end, of splitting the side walls of the cylindrical opposite end of the blank centrally thereof, of Wedging said two split sections apart to form one half of the banjo portion of the housing of channel section, 0t welding the ends of channel section of the banjo portions of two formed blanks to provide a flanged circular banjo portion from which arms of square section support the spindles in aligned relation, and of welding a reinforcing ring on each outer side of the banjo housing.

References Cited in the file of this patent UNITED STATES PATENTS 1,451,401 Murray Apr. 10, 1923 1,873,453 Mogford et al Aug. 23, 1932 2,069,480 Riernenshneider Feb. 2, 1937 2,124,466 Spatta July 19, 1938 2,303,266 Gettig Nov. 24, 1942 2,563,680 Hoffman Aug. 7, 1951 2,625,055 Cudy Jan. 13, 1953 

